Biology subjects

Royall, D. R.

Publications and source records attributed to Royall, D. R..

2 recordsLinked to original sources

bioRxiv2019

Dementia is Associated with a Syndrome of Global Neuropsychiatric Disturbance

ObjectiveGlobal factors have been identified in measures of cognitive performance (i.e., Spearmans g) and psychopathology (i.e., \"General Psychopathology\", \"p\"). Dementia is also strongly determined by the latent phenotype \"{delta}\", derived from g. We wondered if the Behavior and Psychological Symptoms of Dementia (BPSD) might arise from an association between {delta} and p.\n\nMethods{delta} and p were constructed by confirmatory factor analyses in data from the Alzheimers Disease Neuroimaging Initiative (ADNI). {delta} and orthogonal factors representing \"domain-specific\" variance in memory (MEM) and executive function (EF) were regressed onto p and orthogonal factors representing \"domain-specific\" variance in positive (+) and negative (-) symptoms rated by the Neuropsychiatric Inventory Nursing Home Questionnaire (NPI-Q) by multiple regression in a structural equation model (SAM) framework.\n\nResultsModel fit was excellent (CFI = 0.98, RMSEA = 0.03). {delta} was strongly associated with p, (+) and (-) and strongly associated with p (r = -0.57, p<0.001). All three associations were inverse (adverse). Independently of {delta}, MEM was uniquely associated with (+), while ECF was associated with (-). Both associations were moderately strong. ECF was also weakly associated with p.\n\nConclusionsDementia severity ({delta}) derived from general intelligence (g) is specifically associated with general psychopathology (p). This is ps first demonstration in an elderly sample and the first to distinguish the global behavioral and psychological symptoms specific to dementia (BPSSD) from behavioral disturbances arising by way of non-dementing, albeit likely disease-specific, processes affecting domain-specific cognitive and behavioral constructs. Our findings call into question the utility of proposed regional interventions in BPSSD, and point to the need to explore global interventions against dementia-specific behavioral features.

neuroscience↗

bioRxiv2017

Serum proteins can successfully predict self-reported ethnicity: Implications for precision-medicine

The effects of inter-individual variability on disease treatment and prevention are important to the goals of \"precision medicine\" 1. In biomedical research, consideration of racial or ethnic differences allows generation and exploration of hypotheses about interactions among genetic and environmental factors responsible for differential medical outcomes. The US National Institutes of Health, therefore recommends adequate participation of subjects from ethnic minority groups in research studies. Nevertheless, considerable debate has focused on validity of race or ethnicity as biological construct 2. Inconsistent definition of race/ethnicity and insignificant genetic variations between ethnic groups have invited disregard to this construct 3. On the contrary, differences in prevalence, expression and outcomes of various diseases among ethnic groups argue for continued and focused attention to ethnicity as important predicting variable. In context of Alzheimers disease (AD), we have previously reported that ethnicity does moderates the proteomic markers of dementia 4. Here, we attempted to classify and predict selfreported ethnicity (Hispanic or non-Hispanic white, [NHW]) using a limited serum profile of 107 proteins. Random Forest (RF) classification method was able to discriminate those two ethnicities with 95% accuracy and could successfully predict ethnicity in an independent test-set (Area under ROC curve: 0.97). Variable selection method led to a condensed set of six proteins which yielded comparable classification and prediction accuracy. Our results provide preliminary evidence for proteomic variability between ethnic groups, and biological validity of ethnicity construct. Moreover, they also offer an opportunity to exploit these differences towards the objectives of precision medicine.

bioinformatics↗